手机音腔及出音孔的设计计算.ppt

OptimalSoundMatchingSolutionthroughHelmholtzresonatortheory,BasictheoryHelmholtzResonatorwasinventedforsoundanalysisbyH.VONHelmholtz(18211894)Itsapplicationsarevariousfrombell,violin,guitarandbassspeakercabinet.Itfeaturesshorterneckandvolumebottlethanwaveasshownbelow.Specificfrequencydependsonairvolumeinneck(weight)andvolumeinthebottle(spring)Sospecificfrequencyiscalculatedasbelow.a:Necksarea()V:Resonatorvolume()L:Neckslength(m)C:Soundvelocity(344m/s)ThereforeanyshapesofresonatorisnotaffectingResonantFrequency.Ifthevolume&neckslengthissame,theresonatorhassameresonantfrequencyevenindifferentshape.,Basicprinciple,OptimalSoundMatchingSolutionthroughHelmholtzresonatortheory,Ex.1)Whatstheresonantfrequencyincaseofabottlewithouterdia.9.8cm,necklength10cm,neckouterdia.3cm?,Example,OptimalSoundMatchingSolutionthroughHelmholtzresonatortheory,2.Application(1)Insidestructureofhandset,a:Holetotalarea(m2),L:Casethickness(m),V:Frontvolume(m3),C:344m/s(RT20),Application,OptimalSoundMatchingSolutionthroughHelmholtzresonatortheory,(2)Examplemodel:SS1534P-008-SIZE:15mmX3.4H-Fo:850Hz-Ze:8ohm(3)Testconditions*Inputpower:0.1Wat5cm,Basicprinciple,OptimalSoundMatchingSolutionthroughHelmholtzresonatortheory,SS1534P-008GRAPHinBAFFLE,Originaltestresult,OptimalSoundMatchingSolutionthroughHelmholtzresonatortheory,(4)TESTaccordingtosomevariationsBasicStructureAirHolequantityvariationCasethicknessvariationFrontVolumevariationBackVolumevariation,Testcondition,OptimalSoundMatchingSolutionthroughHelmholtzresonatortheory,Basicstructurea:1.55mmX4eaL:1.55mmV:1.2ccC:344m/s(RT20)Backvolume:2.42cc,=3,486Hz,Basicstructure,HandSetMatchingSolutionwithHelmholtzresonator,X:3.0000kHzY:104.23dBZA:LiveCurveTSRfund.,B,K,Mode:TSR,A:FrequencyResponse,MagndBre20.00,Pa/V,100,200,500,1k,2k,5k,10k,Hz,60,70,80,90,100,110,dB,3,486Hz3,000Hz,Testresult,OptimalSoundMatchingSolutionthroughHelmholtzresonatortheory,AirHolequantityvariationa:1.55mmX4ea1.55mmX2eaL:1.55mmV:1.2ccC:344m/s(RT20)Backvolume:2.42cc,=2,465Hz,Airholevariation,OptimalSoundMatchingSolutionthroughHelmholtzresonatortheory,Testresultofairholechanged,HandSetMatchingSolutionwithHelmholtzresonator,Casethicknessvariationa:1.55mmX4eaL:1.55mm2.5mmV:1.2ccC:344m/s(RT20)Backvolume:2.42cc,=2,745Hz,Casethicknesschanged,OptimalSoundMatchingSolutionthroughHelmholtzresonatortheory,Testresultbycasethicknessvariation,OptimalSoundMatchingSolutionthroughHelmholtzresonatortheory,FrontVolumevariationa:1.55mmX4eaL:1.55mmV:1.2cc0.8ccC:344m/s(RT20)Backvolume:2.42cc,=4,269Hz,Frontvolumevariation,OptimalSoundMatchingSolutionthroughHelmholtzresonatortheory,Testresultbyfrontvolumevariation,OptimalSoundMatchingSolutionthroughHelmholtzresonatortheory,BackVolumevariationa:1.55mmX4eaL:1.55mmV:1.2ccC:344m/s(RT20)Backvolume:2.42cc1.5cc,Backvolumevariation,OptimalSoundMatchingSolutionthroughHelmholtzresonatortheory,B,K,Mode:TSR,A:FrequencyResponse,MagndBre20.00,Pa/V,100,200,500,1k,2k,5k,10k,Hz,60,70,80,90,100,110,dB,X:1.3000kHzY:96.65dBZA:LiveCurveTSRfund.,Lossoflowsound,Testresultbybackvolumechanged,OptimalSoundMatchingSolutionthroughHelmholtzresonatortheory,3.ConclusionWecometoconclusionthroughprovedtheoryasfollows:1)Thequantityoffrontairhole,ResonantFrequency2)Frontcasethickness,ResonantFrequency3)Frontvolume,ResonantFrequency4)Backvolume,LowsoundOptimalacousticsolutioninhandsetdesigncanbecomingfromHelmholtzresonatortheory.Incasethatspeakeritselfhasflatfrequencyresponse,specificresonantfrequencyisgeneratingwhenbeingmountedinthehandset.ThenSPLandsoundqualityisdependingonhowtheresonantfrequencyismetwith.Inconclusiontheoptimalresonantfrequencyshouldbesetbetween2KHzand5KHzbecausetheseareaismostsensitiveoneforhumanear.,Analysis&Conclusion,OptimalSoundMatchingSolutionthroughHelmholtzresonatortheory,HANDSETDesignconsiderationsforOptimalSoundMatching1.Thebiggerbackvolumeinspeaker,therichsoundatlowfrequency.2.Soundleakageatfrontcoveriscausingdecreasingsoundatlowfrequency.3.Thebiggersoundholeinhandset,theclearersound.4.Shouldbedesignedfornointerferenceinbetween